Phonograph



April 1, 1923? 1,489,211

. R. HEAD PHONOGRAPH Filed June 22 1920 J ggnv Patented Apr. 1, 1924.

UNITED STATES PATENT ormce.

ROBERT HEAD, OF YONKERS, NEW YORK, ASSIGNOR TO THE AEOL-IAN COMPANY, A

CORPORATION OF CONNECTICUT.

. PHONOGRAPH.

Application filed June 22, 1320. Serial No. 890,866.

To all whom it may concern:

Be it known that I, Bonner :HEAD, a citizen of the United States of America, residing at Yonkers, in the county of \Vestches- 6 ter, State of New York, have invented certain new and useful Improvements in Phonographs, of which the following is a specification.

My present invention relates to improvements in phonographs and more especially to those of the usual or conventional types, having a sound-box, a tone arm and a horn, or equivalent sound amplifier. The primary object of the invention is to provide means whereby the operator or user of the. phonograph may, at will, set or adjust the same to reproduce the sound records with a deep full tone or to reproduce the sound records with a shrill or sharp tone at a. seemingly higher pitch, according to the wishes of the operator or user. These results are accomplished, according to the present invention, preferably by providing one or more openings in the sound conduit immediately adj acent to the rear wall of the sound-box, which opening or openings'communicate with the atmosphere or exterior of the sound conduit, and a valve to cover or uncover, more or less, such opening or openings, as will be determined by the character of the tone de sired, the valve being set or adjusted manually by the operator or user of the phonograph.

To these and other ends, the invention consists in certain improvements and combinations and arrangements of parts, all as will be hereinafter more fully described, the features of novelty being pointed out particularly in the claim at the end of the specification.

In the accompanying drawing Figure 1 represents a section taken diametrically through a sound-box, in the plane of the stylus, and equipped with a tone modifying device constructed in accordance with the present invention;

Figure 2 represents a section taken on the line 2-2 of Figure l, the valve being shown in a position to partially cover the tone controlling openings; and

Figures 3 and 4 are views similar to Figure 2 but showing the valve in positions to completely uncover and to completely cover respectively the tone-controlling openings.

Similar parts are designated by the same reference characters in the several views.

The present invention is applicable generally to the sound-boxes of phonographs or talking machines of all types, although it is preferably applicable to sound-boxes of phonographs which ordinarily reproduce the records with a full deep tone, as distinguished from those which reproduce the records normally with a shrill or relatively sharp tone at a seemingly high pitch. The preferred embodiment of the invention is shown in the accompanying drawing and will be hereinafter described in detail. It is to be understood, however, that the invention is not restricted to the precise construction shown, as equivalent constructions are contemplated and these will be included within the scope of the claim.

In the present instance, the sound-box is of the usual or conventional type, it com-r prises a rear wall 1 having a ring 2 fixed to its forward face, this ring containing or holding in position the usual diaphragm 3 which may be secured within the ring 2 by suitable ring-like members 4:. The stylus bar 5, which carries the stylus or needle 6 is, in the present instance, adapted to the playing of records having lateral sound grooves, it being pivoted at 7 to the ring 2 or casing ofthe sound-box and attached at 8 to the diaphragm. Obviously, the soundbox may he of a type adapted to play the hill-and-dale type of record.

A fitting 9, which serves to attach the sound-box to the usual tone arm, is fixed preferably directly to the rear face of the rear wall 1 of the sound-box. This fitting has a nipple 10 thereon to fit the tone arm and it has an opening 11 therethrough, which is in line with an opening 12 in the rear wall of the sound-box, these openings constituting a conduit for the passage of sound from the rear side of the diaphragm Preferably and as shown, the fitting 9 has an enlarged portion 13, the interior opening in which is larger than the openings 11 and 12, and the tone modifying means of the present invention is'preferably applied to this enlarged portion, which, it is to he observed, is closely adjacent to the diaphragm. Preferably and as shown, this enlarged portion 13 which constitutes a part of the sound-box, is provided with diametrically opposite openings 14 which are adapted to provide direct communication between the interior and the exterior of this enlarged portion, these openings, when uncovered,

establishing communication between the interior of the enlarged portion of the fitting 9 and the atmosphere. These openings, obviously, may be of any suitable number and they are controlled by a valve, whereby they may be completely covered or uncovered, or they may be partially covered and partially uncovered. Preferably and as shown, the valve comprises a sleeve 15 which encircles or substantially encircles and is rotatable on the exterior of the enlarged part 13, the valve being imperforate except for the openings 15 therein, which correspond in position and size to the openings 14. By this arrangement, the valve may be rotated in one direction to a position such as that shown in Figure 3, so that the openings 16 in the valve register with the openings 14, in which case the latter openings will be completely uncovered, the valve may be rotated into a reverse position such as that shown in Figur 4, in which case the openings 16 will be carried out of registration with the openings 14 and the latter will be completely closed to the atmosphere, or the valve may be set in an intermediate position, such as shown in Figure 2, in which case the openings 16 in the valve will partially register with the openings 14 and the latter will be partially opened or partially closed. Suitable means is preferably provided for retaining the valve in any one of these positions, as may be desired, and as shown, a spring plunger 17 is fitted into a lug 18, which is fixed to the sleeve forming the valve, and the periphery of the enlarged por tion 13 of the sound-box is provided with notches or recesses 19, 20 and 21 into any one of which the spring plunger may enter and thus retain the valve in any one of these positions into which it may be set. The inner walls of the outer notches 19 and 21 and both walls of the intermediate notch 20 are preferably beveled, as shown, in order that the spring plunger will ride up these bevels when sufiicient force is applied manually to turn the valve into any one of these positions. A prolongation 22 of the lug 18 is preferably provided, to serve as a handle to enable the valve to be manipulated or adjusted with facility.

When the valve is set in the position shown in Figure 4, the openings 14 willbe closed, and the sound-box will reproduce the records with the normal or usual tone of the phonograph. The invention is pref erably applied to phonographs, the soundboxes and other elements of which are so constructed that the records will be reproduced with a deep full tone. Should the operator or user of the phonograph desire to reproduce a record with a relatively sharp or shrill tone, this effect can be obtained by adjusting the valve into the position as shown substantially in Figure 3, in which case the openings 14 will be uncovered. In playing the phonograph while the valve is adjusted into the latter described position, the tone will be shrill and sharp and it will seemingly have a higher pitch as compared with reproductions made while the valve is adjusted into the position shown in Figure 4, this difference in tone and seeming difference in pitch being due probably to the circumstance that the upper partials or components of the sound are caused to preponderate or to be emphasized. Intermediate effects can be obtained by setting the valve in an intermediate position, in which case the openings 14 will be partially covered and partially uncovered, as, for example, as shown in Figure 2.

Each of the tone-modifying openings 14 is preferably of a length equal substantially to the diameter of the sound conduit formed by the openings 11 and 12, in order to secure the most desirable modification of the tone, and it is also preferable to locate these openings in opposite positions. By providing an enlarged portion 13 for these tone modifying openings, these openings may be made of sumcient circumferential length and a valve in the form of a rotatable sleeve may be used to cover and uncover them. 7

It is desirable to locate the opening or openings 1.4 as close to the diaphragm of the soundbox as practicable, as it has been found that the desired modification of the tone, as hereinbefore described, is accomplished most effectively in this way. It has also been found that the quality or charactor of tone can be modified as herein described, without causing any substantial change in the volume of the reproduced sound.

I claim as my invention In a phonograph, a sound box having a rear wall opposite to the diaphragm, a sound conduit leading from the space between said wall and the diaphragm, said conduit having an enlarged portion therein provided with a circumferentially extending slot which is located substantially at the junction ofsaid enlarged portion with said space, said slot extending through the wall of the enlarged portion of the conduit to establish communication between the interior and the exterior of the enlarged portion of the conduit, the length of said slot being substantially equal to the diameter of the sound conduit.

In testimony whereof I have hereunto set my hand.

ROBERT HEAD. 

